Control installation for combustion engines

ABSTRACT

A control installation for internal combustion engines in which vacuum taken from the suction line is used for the purpose of adjusting the ignition timing in the distributor and for achieving a thrust boost at the throttle valve whereby an electric control circuit is provided which controls in dependence of influencing magnitudes of the engine, such as temperature and rotational speed, two solenoid valves that are connected in the vacuum line so that the ignition point is shifted and the thrust boost of the throttle valve is achieved.

Quilted States Patent Lena [54] CONTROL ENSTALLATION FOR COWUSTION ENGINES [72] Inventor: Siegfried Lenz, Wailblingen, Germany [73] Assignee: Daimler-Benz Aktiengesellschaft, Stuttgart-Untertuerkheim, Germany [22] Filed: June 25, 1970 [21] Appl. No.: 49,816

[30] Foreigi Application Priority Data July 2, 1969 Germany ..P 19 33 507.0

[52] US. Cl. ..123/117 A, 123/1465 A [51] int. Cl .;F02b 5/00 [58] Field oi Search ..123/117A [56] References Cited UNITED STATES PATENTS 3,559,666 2/1971 Walker ..123/117 A 3,272,191 9/1966 Walker ..123/117 A 3,547,089 12/1970 Pierlot ..123/117 A 1 Aug. 29, 1972 3,301,242 1/1967 Candelise ..123/117 A 3,027,884 4/1962 Bale et al. ..123/117 A 1,761,513 6/1930 Arthur ..123/117A FOREIGN PATENTS OR APPLICATIONS 634,298 6/1935 Germany ..123/117 A Primary ExaminerLaurence M. Goodridge Assistant ExaminerCort R. Flint AttorneyCraig and Antonelli ABSTRACT A control installation for internal combustion engines in which vacuum taken from the suction line is used for the purpose of adjusting the ignition timing in the distributor and for achieving a thrust boost at the throttle valve whereby an electric control circuit is provided which controls in dependence of influencing magnitudes of the engine, such as temperature and rotational speed, two solenoid valves that are connected in the vacuum line so that the ignition point is shifted and the thrust boost of the throttle valve is achieved.

26 Claims, 2 Drawing Figures CQNTROL WSTALLATION FGR COUSTION ENGINES The present invention relates to a control installation for internal combustion engines in which an adjustment of the ignition point or sparking instant at the ignition distributor and a thrust lift or boost of the throttle valve takes place by the vacuum taken off from the suction line.

Since the development of the combustion in the cylinder of an engine requires a certain time and the progress of the combustion is influenced by characteristic magnitudes such as pressure, temperature, air moisture, rotational speed of the crankshaft, etc., one seeks in each load range of the engine to shift the ignition point in each cylinder relative to the upper deadcenter position in such a manner that a clean, nonknocking or non-ringing combustion results and the exhaust gases contain as few as possible non-combusted exhaust gas components such as hydrocarbons, nitrogen oxides and carbon oxides.

Spark advance and retard mechanisms are known in the prior art which operate either as centrifugal force ignition adjusting mechanism or as vacuum ignition adjusting mechanism. The centrifugal force-adjusting mechanism operates automatically independence on the engine rotational speed in that two flyweights transmit their movement which is directed outwardly during the rotation, by way of an entrainment member to the breaker cam which is rotated as a result thereof and thereby opens the contact-breaker points earlier in time. With a decreasing rotational speed, the flyweights are pulled back into their rest position by springs whereby the reverse effect occurs.

With the vacuum-adjusting mechanism, a pull-rod operatively connected with a diaphragm of the vacuum box changes the position of the contact-breaker points whereby an ignition timing adjustment is achieved. The vacuum box is in communication with the suction pipe of the carburetor by way of a line, through which vacuum is fed to the diaphragm from two places of the carburetor vacuum; namely, from the Venturi nozzle and from the throttle valve. Finally, spark advance and retard mechanisms are known in the prior art which fonn a combination of a vacuum-adjusting mechanism and of a centrifugal force-adjusting mechanism. With all known spark advance and retard mechanisms, the constructive expenditures are very large and, additionally, the known spark advance and retard mechanisms tend toward faulty operation which may considerably influence the course of combustion. Furthermore, all engine characteristic magnitudes are not taken into consideration in the control of the ignition point or sparking instant, such as, for example, the temperature.

it is the aim of the present invention to avoid the disadvantages of the prior art spark advance and retard mechanisms and to achieve with simple constructive means the control of the ignition point and a simultaneous thrust lift or boost of the throttle valve.

The underlying problems are solved by the present invention in that an electric control circuit is provided which controls in dependence on engine influencing magnitudes, preferably in dependence on the temperature and the rotational speed, two magnetic or solenoid valves that are arranged in the vacuum line so that the ignition point or firing instant is adjusted and the thrust boost of the throttle valve is achieved. According to a very advantageous type of construction of the present invention, at least two thermal-switches, a rotational speed relay, and the solenoid valves may be arranged in the electric control circuit. It has thereby proved as very appropriate that the thermal-switches close the circuit within a temperature range of preferably about 15 to C. and render the installation ready for operation. This measure can be achieved very simply in that one thermal-switch closes the circuit at a temperature of about 15 C. and the other thermal-switch opens the circuit at a temperature above 100 C. This temperature range is preferably so selected because with a sealed cooling water system, the cooling water begins to boil at about 100 C.

The rotational speed relay provided in the circuit may consist preferably of two control switches which control each a respective solenoid valve. The two solenoid valves of which one is constructed as a three-way valve and controls the ignition timing and of which the other solenoid valve is constructed preferably as a twoway valve and controls the thrust lift of the throttle valve in a conventional manner, are in communication with the suction pipe by way of a vacuum line. However, it is also feasible within the scope of the present invention that each solenoid valve is in communication with the suction pipe by way of a separate line whereby the vacuum can possibly be tapped at different places of the suction pipe. g

It is very advantageous if the control switch of the rotational speed relay operatively connected with the three-way magnetic valve energizes the magnetic valve, for example, within a rotational speed range of n n to n 2,400 rpm. It is also advantageous if the control switch of the rotational speed relay operatively connected with the two-way magnetic valve energizes the magnetic valve, for example, within a rotational speed range of n 1,800 to n nm rpm- The preselected rotational speed ranges, indicated hereinabove only as illustrative examples, are determined according to the design of the engine and may possibly be shifted to higher as well as to lower rotational speeds. The electric energizing circuit of each magnetic valve may thus be opened by at least three electric switches, and more particularly, by the two thermal-switches and a corresponding control switch of the rotational speed relay. However, it is also within the purview of the present invention that still further switches are arranged in each energizing circuit of a magnetic valve which are controlled by other influencing magnitudes.

According to a still further advantageous feature of the present invention, a vacuum box, adapted to be acted upon on both sides with vacuum, is provided in the vacuum line at the distributor which is controlled by the three-way magnetic valve.

An armature is advantageously guided on the inside of a winding or coil in the three-way magnetic valve, which is provided at its two ends with one valve seat each so that a respective one of the two vacuum lines in communication with the vacuum box of the distributor is closed in the energized condition by means of the magnetic force and in the de-energized condition by means of a spring force. It is thereby appropriate that the three-way magnetic valve opens up in the energized condition the vacuum line to the side of the vacuum box which effects a retardation of the ignition point whereas in the deenergized condition the three-way magnen'c valve opens up correspondingly the line to the side of the vacuum box which effects an advance of the ignition point. The diaphragm acted upon with the vacuum in the vacuum box effects in a conventional manner by way of a lever mechanism an adjustment of the contact-breaker points. Since with a sudden closing of the three-way magnetic valve, the vacuum would remain in the vacuum box, the box is advantageously provided with a venting means in communication with the atmosphere so that a pressure equalization can take place.

The other valve constructed as conventional twoway magnetic valve which is also in communication with the suction pipe by way of the vacuum line and which is controlled by a control switch of the rotational speed relay, opens up in the de-energized condition the vacuum line to the vacuum regulator at the carburetor so that the latter operates in the normal condition. In an energized condition, the armature is pulled into the coil and atmospheric air flows into the magnetic valve and throttled into the vacuum line which, by reason of the very small selected throttling cross section is not harmful.

Accordingly, it is an object of the present invention to provide a control system for internal combustion engines which avoids the aforementioned shortcomings and drawbacks encountered in the prior art.

Another object of the present invention resides in a control installation for internal combustion engines which properly controls the ignition point by simple means, taking into consideration all the pertinent characteristic magnitudes that require consideration.

A further object of the present invention resides in a control system for internal combustion engines which assures as fault-free an operation of the combustion progress as possible.

Still another object of the present invention resides in an ignition advance and retard mechanism which operates satisfactorily under all driving conditions.

These and further objects, features, and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, one embodiment in accordance with the present invention, and wherein:

FlG. l is a schematic view of the over-all installation in accordance with the present invention including the electric control circuit thereof; and

FIG. 2 is a partially broken-away view of the threeway magnetic valve used with the control installation in accordance with the present invention.

Referring now to the drawing wherein like reference numerals are used throughout the two views to designate like parts, and more particularly to H6. 1, this figure illustrates the electric control circuit 1 which controls the solenoid valves 2 and 3 in dependence on the temperature and the rotational speed. The magnetic valves 2 and 3 are arranged in the vacuum line 4. Two thermal switches t5 and 7, a rotational speed relay generally designated by reference numeral 8, and the magnetic valves 2 and 3 are arranged in the electric control circuit 1 which is fed by the voltage source 5.

The solenoid valves 2 and 3 may be connected advantageously in the control circuit 1 by means of conventional plugs 9.

The switch 6 closes the circuit at a temperature higher than about 15 C. whereas the switch 7 opens the circuit at a temperature higher than about C. The rotational speed relay 8 consists of two control switches 10 and 11 which control each a respective magnetic valve 2 and 3. The magnetic valve 2 is constructed as three-way valve and controls the ignition timing adjustment. The magnetic valve 3 is constructed as two-way valve and in a conventional manner the thrust lift of the throttle valve 12 of the carburetor 13 with the aid of a vacuum regulator 14. The control switch 10 of the rotational speed relay 8 controls the magnetic valve, for example, within a rotational speed range of n ri to n 2,400 rpm. The control switch 13 of the rotational speed relay 8 controls the magnetic valve 3, for example within a rotational speed range of n 1,800 to n =n A vacuum box 18 is provided at the distributor 17 in the vacuum lines 15 and 16 which is adapted to be acted upon on both sides with the vacuum and which is controlled by the magnetic valve 2.

The magnetic valve 2 is shown in detail in FIG. 2. A winding 19 can be recognized on the inside of the magnetic valve 2, within which is guided the armature 20.

The armature 20 includes at the two ends thereof a I valve seat 21 and 22, by means of which it is able to close a respective one of the two vacuum lines 15 and 16. In the energized condition, the armature 20 closes the vacuum line 16 in that it is pulled into the winding 19 against the spring force of the spring 23, until it seats on the orifice of the vacuum line T6. in the de-energized condition of the magnetic valve 2 the spring 23 presses the armature 20 against the orifice of the vacuum line 15 so that the latter is closed.

OPERATION The operation of the control system is to be explained by reference to one example. The position of the control installation illustrated in FIG. 1 is valid for a rotational speed smaller than 1,800 rpm. and for a temperature which lies between about 15 C. and about 100 C. The control installation is ready for operation by the closing of the thermal switches 6 and 7. Since the rotational speed lies below 1,800 rpm, the control switch 111 is open and the control switch 10 is closed so that the magnetic valve 2 is energized and the magietic valve 3 is de-energized. The magnetic valve 2 closes in the energized condition the vacuum line 16 so that the vacuum, which is bled from the suction line of the carburetor 1.3 by way of the vacuum line 4, acts fully on the side of the vacuum box 18 in communication with the vacuum line 15 and a retardation of the ignition point takes place.

it follows therefrom that with lower rotational speed the ignition point is shifted closer to the top deadcenter position so that the mixture can be well prepared prior to the ignition. Since the magnetic valve 3 is de-energized and the armature thereof closes the opening in communication with the atmosphere, the vacuum acts on the vacuum regulator 14 which then operates in the normal condition.

Widi a cooling water temperature, for example, smaller than about C., the switch 6 opens and the circuit to the two magnetic valves 2 and 3 is interrupted; this means that the armature closes in the de-energized condition the vacuum line 15 and the vacuum effects by way of the vacuum line 16 with the aid of the vacuum box 18 an advance of the ignition point. The magnetic valve 3 does not change its positron.

With a cooling water temperature about 100 C. the thermal switch 7 interrupts the control circuit and the two magnetic valves 2 and 3 are de-energized. One obtains thereby again an advanced ignition and especially in the lower rotational speed range, for example, during idling, the boiling of the radiator can be avoided.

While I have shown and described only one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to those skilled in the art, and I therefore do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

I claim:

1. in an internal combustion engine having adjustable throttle valve means including a throttle valve arranged in a suction line of the engine, distributor means having an adjustable ignition point and connecting vacuum line means connecting said adjustable throttle valve means and said distributor means to said suction line whereby the thrust boost at the throttle valve and the adjustment of the ignition point at the distributor means takes place by the vacuum taken off from the suction line, the improvement comprising a control installation including a first magnetic valve means arranged in said connecting means for controlling the application of the vacuum of said suction line to said adjustable throttle valve means, a second magnetic valve means arranged in said connecting means for controlling the application of the vacuum of said suction line to said distributor means, and electric control circuit means responsive to operating magnitudes of the engine for actuating each of said magnetic valve means independently of the actuation of the other of said magnetic valve means such that the adjustment of the ignition point at the distributor means and the adjustment of the thrust boost of the throttle valve means is achieved independently of the other.

2. A control installation according to claim 1, characterized in that said operating magnitudes of the engine include the temperature and rotational speed.

3. A control installation for internal combustion engines in which an adjustment of the ignition point at the distributor and a thrust boost at the throttle valve takes place by the vacuum taken off from the suction line, characterized by an electric control circuit means operable to control two magnetic valve means in dependence of engine influencing magnitudes, said magnetic valve means being arranged in vacuum line means so that the ignition point is adjusted and the thrust boost of the throttle valve is achieved, at least two thermal switch means, a rotational speed relay means and said magnetic valve means being arranged in said electric control circuit means.

4. A control installation according to claim 3, characterized in that said thermal switch means close the circuit means within a predetermined temperature range and thereby render the installation ready for operation.

5. A control installation according to claim 4, characterized in that said temperature range is about 15 C. to about C.

6. A control installation according to claim 4, characterized in that said rotational speed relay means includes at least two control switch means, each control switch means controlling a respective magnetic valve means.

7. A control installation according to claim 6, characterized in that one magnetic valve means is constructed as three-way valve means and controls the ignition timing.

8. A control installation according .to claim 7, characterized in that the other magnetic valve means is constructed as two-way valve means and controls the thrust boost at the throttle valve.

9. A control installation according to claim 8, characterized in that the control switch means of the rotational speed relay means operatively connected with the three-way magnetic valve means engages the three-way magnetic valve means within a predetermined rotational speed range. 10. A control installation according to claim 9, wherein said last-mentioned rotational speed range is from n n to about n 2,400 rpm.

11. A control installation according to claim 9, characterized in that the control switch means of the rotational speed relay means operatively connected with the two-way magnetic valve means engages the two-way magnetic valve means within a predetermined rotational speed range.

12. A control installation according to claim 11, characterized in that said last-mentioned rotational speed range is from about 1,800 to about n rpm. I

13. A control installation according to claim 11, characterized in that a vacuum box means adapted to be acted upon with vacuum on both sides thereof is provided at the distributor in the vacuum line means, which is controlled by the three-way magnetic valve means.

14. A control installation according to claim 13, characterized in that said three-way magnetic valve means includes a coil and an armature guided within said coil which is provided at both of its ends with a valve seat, and in that a respective one of two vacuum line means in operative connection with the vacuum box means is closed in the energized condition by the magnetic force and in the de-energized condition by the spring force of a spring.

15. A control installation according to claim 14, characterized in that the three-way magnetic valve means opens up in the energized condition the vacuum line means to the side of the vacuum box means which brings about a retardation of the timing whereas in the de-energized condition, it correspondingly opens up the vacuum line means to the side of the vacuum box means which effects an advance of the ignition point.

16. A control installation according to claim 15, characterized in that said influencing magnitudes include the temperature and rotational speed.

17. A control installation according to claim 3, characterized in that said rotational speed relay means includes at least two control switch means, each control switch means controlling a respective magnetic valve means.

18. A control installation according to claim 1, characterized in that one magnetic valve means is constructed as three-way valve means and controls the ignition timing.

19. A control installation according to claim 1, characterized in that one magnetic valve means is constructed as two-way valve means and controls the thrust boost at the throttle valve.

26 A control installation according to claim 18, characterized in that the electric circuit means includes rotational speed relay means having control switch means, the control switch means of the rotational speed relay means operatively connected with the three-way magnetic valve means engages the three-way magnetic valve means within a predetermined rotational speed range.

21. A control installation according to claim 20, wherein said last-mentioned rotational speed range is from n ri to n 2,400 rpm.

22. A control installation according to claim 19, characterized in that the electric circuit means includes rotational speed relay means having control switch means, the control switch means of the rotational speed relay means operatively connected with the two-way magnetic valve means engages the two-way magnetic valve means within a predetermined rotational speed range.

23. A control installation according to claim 22, characterized in that said last-mentioned rotational speed range is from about n L800 to about in rpm.

24. A control installation according to claim 18, characterized in that a vacuum box means adapted to be acted upon with vacuum on both sides thereof is provided at the distributor in the vacuum line means, which is controlled by the three-way magnetic valve means.

26. A control installation according to claim 24, characterized in that said three-way magnetic valve means includes a coil and an armature guided within said coil which is provided at both of its ends with a valve seat, and in that a respective one of two vacuum line means in operative connection with the vacuum box means is closed in the energized condition by the magnetic force and in the de-energized condition by the spring force of a spring.

26. A control installation according to claim 24, characterized in that the three-way magnetic valve means opens up in the energized condition the vacuum line means to the side of the vacuum box means which brings about a retardation of the timing whereas in the de-energized condition, it correspondingly opens up the vacuum line means to the side of the vacuum box means which effects an advance of the ignition point. 

1. In an internal combustion engine having adjustable throttle valve means including a throttle valve arranged in a suction line of tHe engine, distributor means having an adjustable ignition point and connecting vacuum line means connecting said adjustable throttle valve means and said distributor means to said suction line whereby the thrust boost at the throttle valve and the adjustment of the ignition point at the distributor means takes place by the vacuum taken off from the suction line, the improvement comprising a control installation including a first magnetic valve means arranged in said connecting means for controlling the application of the vacuum of said suction line to said adjustable throttle valve means, a second magnetic valve means arranged in said connecting means for controlling the application of the vacuum of said suction line to said distributor means, and electric control circuit means responsive to operating magnitudes of the engine for actuating each of said magnetic valve means independently of the actuation of the other of said magnetic valve means such that the adjustment of the ignition point at the distributor means and the adjustment of the thrust boost of the throttle valve means is achieved independently of the other.
 2. A control installation according to claim 1, characterized in that said operating magnitudes of the engine include the temperature and rotational speed.
 3. A control installation for internal combustion engines in which an adjustment of the ignition point at the distributor and a thrust boost at the throttle valve takes place by the vacuum taken off from the suction line, characterized by an electric control circuit means operable to control two magnetic valve means in dependence of engine influencing magnitudes, said magnetic valve means being arranged in vacuum line means so that the ignition point is adjusted and the thrust boost of the throttle valve is achieved, at least two thermal switch means, a rotational speed relay means and said magnetic valve means being arranged in said electric control circuit means.
 4. A control installation according to claim 3, characterized in that said thermal switch means close the circuit means within a predetermined temperature range and thereby render the installation ready for operation.
 5. A control installation according to claim 4, characterized in that said temperature range is about 15* C. to about 100* C.
 6. A control installation according to claim 4, characterized in that said rotational speed relay means includes at least two control switch means, each control switch means controlling a respective magnetic valve means.
 7. A control installation according to claim 6, characterized in that one magnetic valve means is constructed as three-way valve means and controls the ignition timing.
 8. A control installation according to claim 7, characterized in that the other magnetic valve means is constructed as two-way valve means and controls the thrust boost at the throttle valve.
 9. A control installation according to claim 8, characterized in that the control switch means of the rotational speed relay means operatively connected with the three-way magnetic valve means engages the three-way magnetic valve means within a predetermined rotational speed range.
 10. A control installation according to claim 9, wherein said last-mentioned rotational speed range is from n nmin to about n 2,400 rpm.
 11. A control installation according to claim 9, characterized in that the control switch means of the rotational speed relay means operatively connected with the two-way magnetic valve means engages the two-way magnetic valve means within a predetermined rotational speed range.
 12. A control installation according to claim 11, characterized in that said last-mentioned rotational speed range is from about n 1,800 to about n nmax rpm.
 13. A control installation according to claim 11, characterized in that a vacuum box means adapted to be acted upon with vacuum on both sides thereof is provided at the distributor in the vacuum line means, which is controlled by the three-way magnetic valve means.
 14. A control installation according to claim 13, characterized in that said three-way magnetic valve means includes a coil and an armature guided within said coil which is provided at both of its ends with a valve seat, and in that a respective one of two vacuum line means in operative connection with the vacuum box means is closed in the energized condition by the magnetic force and in the de-energized condition by the spring force of a spring.
 15. A control installation according to claim 14, characterized in that the three-way magnetic valve means opens up in the energized condition the vacuum line means to the side of the vacuum box means which brings about a retardation of the timing whereas in the de-energized condition, it correspondingly opens up the vacuum line means to the side of the vacuum box means which effects an advance of the ignition point.
 16. A control installation according to claim 15, characterized in that said influencing magnitudes include the temperature and rotational speed.
 17. A control installation according to claim 3, characterized in that said rotational speed relay means includes at least two control switch means, each control switch means controlling a respective magnetic valve means.
 18. A control installation according to claim 1, characterized in that one magnetic valve means is constructed as three-way valve means and controls the ignition timing.
 19. A control installation according to claim 1, characterized in that one magnetic valve means is constructed as two-way valve means and controls the thrust boost at the throttle valve.
 20. A control installation according to claim 18, characterized in that the electric circuit means includes rotational speed relay means having control switch means, the control switch means of the rotational speed relay means operatively connected with the three-way magnetic valve means engages the three-way magnetic valve means within a predetermined rotational speed range.
 21. A control installation according to claim 20, wherein said last-mentioned rotational speed range is from n nmin to n 2, 400 rpm.
 22. A control installation according to claim 19, characterized in that the electric circuit means includes rotational speed relay means having control switch means, the control switch means of the rotational speed relay means operatively connected with the two-way magnetic valve means engages the two-way magnetic valve means within a predetermined rotational speed range.
 23. A control installation according to claim 22, characterized in that said last-mentioned rotational speed range is from about n 1,800 to about n nmax rpm.
 24. A control installation according to claim 18, characterized in that a vacuum box means adapted to be acted upon with vacuum on both sides thereof is provided at the distributor in the vacuum line means, which is controlled by the three-way magnetic valve means.
 25. A control installation according to claim 24, characterized in that said three-way magnetic valve means includes a coil and an armature guided within said coil which is provided at both of its ends with a valve seat, and in that a respective one of two vacuum line means in operative connection with the vacuum box means is closed in the energized condition by the magnetic force and in the de-energized condition by the spring force of a spring.
 26. A control installation according to claim 24, characterized in that the three-way magnetic valve means opens up in the energized condition the vacuum line means to the side of the vacuum box means which brings about a retardation of the timing whereas in the de-energized condition, it correspondingly opens up the vacuum line means to the side of the vacuum box means which effects an advance of the ignition point. 